They are connected words. "to hear" is the bodily process using our ears; it is done without thinking about it. "to listen" is the act of using that process; we must actively do this. Examples: I can hear music. Listen to this beautiful song.

Listening means you pay attention. Also, you use a preposition (to/for) after listen. If you use hear, you must tell us what you hear. I hear music. I listen to music. I listened for my friend's voice. (= I was waiting and listening.)

They are not the same. You listen for a sound, but you may or may not hear it. To hear is the end result of listening.

Hear is a result and listen is a process.

To hear = oir To listen = escuchar (Más o menos)